Field help (VALTYP) 

This information is used to define whether the value is an amount or a percentage.
When it is a percentage, it can be combined with percentages previously defined, or applied in series to these elements.
There are thus two choices in this case: % combined, and % series.

Examples and where-used cases

The distinction between combined percentage and percentage in series is useful only for columns that are after the first one in the price list structure.